The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 09, 2016
Filed:
Dec. 02, 2010
Antoine Hoxha, Neuville-en-condroz, BE;
Dorina Fati, Neuville-en-condroz, BE;
Antoine Hoxha, Neuville-en-condroz, BE;
Dorina Fati, Neuville-en-condroz, BE;
PRAYON TECHNOLOGIES, Engis, BE;
Abstract
The invention relates to a method for producing phosphoric acid, including: attacking phosphate rock by means of sulfuric acid between 70° and 90° C. with formation of a first calcium sulfate dihydrate crystal slurry, the aqueous acid phase of said slurry having free POcontent between 38 and 50 wt % and free SOcontent that is less than 0.5 wt % and greater than 0.05 wt %; converting said first slurry by means of heating at a temperature greater than 90° C., thus giving rise to a second slurry formed of calcium sulfate hemihydrate crystals; and, within the second slurry, separating a produced phosphoric acid, having a free SOcontent that is less than 2%, and a calcium sulfate hemihydrate filter cake.